precedent vs prior

precedent

adj
  • Happening or taking place earlier in time; previous or preceding. 

verb
  • To provide precedents for. 

  • To be a precedent for. 

noun
  • The previous version. 

  • A decided case which is cited or used as an example to justify a judgment in a subsequent case. 

  • An established habit or custom. 

  • An act in the past which may be used as an example to help decide the outcome of similar instances in the future. 

prior

adj
  • Advance; previous; coming before. 

  • Former, previous. 

adv
  • Previously. 

noun
  • A high-ranking member of a monastery, usually lower in rank than an abbot. 

  • A prior probability distribution, one based on information or belief before additional data is collected. 

  • A belief supported by previous evidence or experience that one can use to make inferences about the future. 

  • A chief magistrate in Italy. 

  • A previous arrest or criminal conviction on someone's record. 

How often have the words precedent and prior occurred in a corpus of books? (source: Google Ngram Viewer )